Lynch Pathway



MLH1 loss determined by IHC is observed in dMMR tumours from Lynch syndrome patients but also a significant minority of sporadic tumours. MLH1 promoter hypermethylation is a common somatic epimutation in sporadic tumours yet is rare in Lynch syndrome tumours where the ‘first hit’ is inherited. MLH1 promoter hypermethylation can be used to stratify Lynch syndrome risks in patients, particularly those which meet revised Bethesda criteria.

Please refer to the National Genomic Test Directory for Cancer here.

Reporting times

MLH1 Hypermethylation                         21 calendar days

Sample Requirements

  • Lymphocyte samples are accepted in order to test for rare cases of Lynch syndrome due to constitutional MLH1 promoter hypermethylation.

Requesting a test

Please refer to our Sample Requirements section before sending any samples to us for testing.

Please refer to the flow chart on this page and use the relevant form below: